// Base64 JavaScript decoder
// Copyright (c) 2008-2021 Lapo Luchini <lapo@lapo.it>

// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

var decoder: any[] | undefined, // populated on first usage
  haveU8 = typeof Uint8Array == 'function';

export const decode = function (a: any) {
  var isString = typeof a == 'string';
  var i;
  if (decoder === undefined) {
    var b64 =
        'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
      ignore = '= \f\n\r\t\u00A0\u2028\u2029';
    decoder = [];
    for (i = 0; i < 64; ++i) decoder[b64.charCodeAt(i)] = i;
    for (i = 0; i < ignore.length; ++i) decoder[ignore.charCodeAt(i)] = -1;
    // RFC 3548 URL & file safe encoding
    decoder['-'.charCodeAt(0)] = decoder['+'.charCodeAt(0)];
    decoder['_'.charCodeAt(0)] = decoder['/'.charCodeAt(0)];
  }
  var out: any = haveU8 ? new Uint8Array((a.length * 3) >> 2) : [];
  var bits = 0,
    char_count = 0,
    len = 0;
  for (i = 0; i < a.length; ++i) {
    var c = isString ? a.charCodeAt(i) : a[i];
    if (c == 61)
      // '='.charCodeAt(0)
      break;
    c = decoder[c];
    if (c == -1) continue;
    if (c === undefined) throw 'Illegal character at offset ' + i;
    bits |= c;
    if (++char_count >= 4) {
      out[len++] = bits >> 16;
      out[len++] = (bits >> 8) & 0xff;
      out[len++] = bits & 0xff;
      bits = 0;
      char_count = 0;
    } else {
      bits <<= 6;
    }
  }
  switch (char_count) {
    case 1:
      throw 'Base64 encoding incomplete: at least 2 bits missing';
    case 2:
      out[len++] = bits >> 10;
      break;
    case 3:
      out[len++] = bits >> 16;
      out[len++] = (bits >> 8) & 0xff;
      break;
  }
  if (haveU8 && out.length > len) {
    // in case it was originally longer because of ignored characters
    out = out.subarray(0, len);
  }
  return out;
};

export const pretty = function (str: string) {
  // fix padding
  if (str.length % 4 > 0)
    str = (str + '===').slice(0, str.length + (str.length % 4));
  // convert RFC 3548 to standard Base64
  str = str.replace(/-/g, '+').replace(/_/g, '/');
  // 80 column width
  return str.replace(/(.{80})/g, '$1\n');
};

export const re =
  /-----BEGIN [^-]+-----([A-Za-z0-9+/=\s]+)-----END [^-]+-----|begin-base64[^\n]+\n([A-Za-z0-9+/=\s]+)====|^([A-Za-z0-9+/=\s]+)$/;

export const unarmor = function (a: any) {
  var m = re.exec(a);
  if (m) {
    if (m[1]) a = m[1];
    else if (m[2]) a = m[2];
    else if (m[3]) a = m[3];
    else throw 'RegExp out of sync';
  }

  return decode(a);
};
